Similarity search techniques using acoustic features are known, which allow the user to search multiple songs for a desired song. Various kinds of such techniques are being studied. In such similarity search techniques, the MFCC (Mel-Frequency Cepstrum Coefficient) known in the model learning for audio recognition is widely used as the features of the songs.
Non-patent document 1 describes a technique in which distance calculation is performed based upon the features when performing clustering using k-means. Non-patent document 2 describes a tool which is known as HTK for calculating the MFCC. Non-patent document 3 describes a method for calculating the features that correspond to the MFCC based upon the song data in the MP3 (Mpeg-1 Audio Layer-3) format.